GARDENING : Azaleas’ Care Shouldn’t be Shrubbed Off

Give azaleas their basic requirements, and they’ll thrive in just about any garden and produce months of colorful blooms. But they can also languish or even die if they’re not treated properly.

“Although they’re not the easiest shrubs to grow in Southern California, once they’re planted correctly, they should be no problem,” said Nick Milfeld of Milfeld’s Nursery, specializing in azaleas for more than 40 years. The Riverside-based wholesale azalea grower supplies plants to nurseries throughout Southern California and grows more than 100 varieties on his 20-acre site.

“You can’t just drop an azalea into the ground and expect great results,” Milfeld cautioned. “They require acid soil, and since most soil in this area is alkaline, as is the water, adjustments have to be made.”

Azaleas need more air in their root zone than any other garden plant, and they also require constant moisture supply. They thrive in woodland areas where these conditions exist naturally, but the home gardener can simulate this by adding plentiful amounts of organic amendment in the form of peat moss and redwood bark mulch to the planting site.

Milfeld recommends digging a shallow, wide hole for the azalea shrub. Mix only 20% of the garden soil with peat moss, and plant the azalea with the top of the root ball at least 1 inch above the soil. Never allow soil to wash in and bury the stems. That’s one of the fastest ways to kill the shrub since it promotes stem or root rot.

Azalea roots grow close to the surface, so the plants benefit from mulch placed around the base, but not touching the stem. Redwood bark mulch is recommended since it is acid-based and breaks down slowly. Avoid steer manure; it can burn the roots.

The other major cause of premature death of azaleas is over watering.

“Check the soil around the plant before watering,” Milfeld advised. “Water only when the top 1 inch of the peat moss area is dry or if the plant looks slightly wilted.”

Azaleas like humid conditions, and this can be simulated by sprinkling the plant very lightly, just enough to moisten the leaves but not soak the roots.

It is easy to see if an azalea plant is not thriving. A common problem is chlorosis, in which the plant lacks iron. It is indicated by a yellowing of the leaves while the veins remain green. Chlorosis is caused by several factors, including excessive buildup of salts in the soil or over watering. Apply iron chelate according to product directions to correct the iron deficiency.

Azaleas require regular fertilizer for best bloom production. Apply a fertilizer specifically formulated for azaleas and follow the manufacturer’s directions. Begin fertilizing at the beginning of blooming, and repeat monthly until September. Cottonseed meal can also be used as an organic fertilizer. Milfeld recommends it especially for container-grown azaleas, because the meal won’t burn the roots or encourage rampant growth.

Azaleas are technically rhododendrons. There are about 5,000 named varieties of azaleas, although only about 500 are suited to Southern California’s climate.

“Often, people from the East Coast try to grow their favorite varieties here, but they don’t realize that only certain varieties will thrive in our unique climate,” Milfeld said.

Certain azalea varieties are best suited for shade gardens, and prefer eastern or northern exposures. There are also varieties that will grow in full sun along the coast or partial shade inland.

Hybridizers have been hard at work to develop new colors of azaleas, along with varieties that will withstand full sun.

“Hybridizers are trying to develop azaleas with longer bloom periods and more sun tolerance,” said hybridizer Tom Nuccio of Nuccio’s Nursery in Altadena. The world-famous nursery sells more than 400 varieties of azaleas.

“We’re also trying to develop yellow and blue azaleas,” Nuccio said. “There are deciduous yellow azalea shrubs, but they don’t do well in Southern California, so we’re trying to come up with evergreen yellow azaleas that will grow here. It may be a long while before we’re successful.”

Azaleas can make dramatic additions to a landscape, bringing colors such as red, purple, orange-blends, and other vibrant colors to a shady area. There are also several varieties of white azaleas that add light to an otherwise dark garden spot.

A mass planting of the same variety can make a strong statement. With pruning, they can be grown as hedges along a walkway or driveway. There are even tree forms of azaleas to add two-story color. These consist of azalea plants budded on 36-inch trunks.

Milfeld grows what he terms “poodles.” He buds three azalea plants on 36-inch trunks, each 1 foot apart. The effect is three balls of vertical color reaching a height of up to 5 feet when in bloom.

“It’s a formal look that goes very well with a Colonial-type house or as a focal point in a formal garden,” Milfeld said.

Many varieties grow very well in hanging baskets or containers. The key for successful container gardening is to select varieties that won’t grow too large.

Ted Mayeda of M&M; Nursery in Orange recommends the following varieties as some of the easiest to grow in Orange County:

* Red Wing, also called Red Bird, the most popular and easiest to grow--red

* Alaska--white

* California Sunset--variegated orange and white

* Formosa--lavender

* George Tabor--orchid pink

* Happy Days--purple

Milfeld favors the entire California series of Belgian Indica azaleas, shade-loving varieties, since they bloom up to six months, have large double flowers, and are relatively easy to grow. He recommends California Beauty, California Pink Dawn, California Peach and California Snow. Their colors are variations of pink or coral tones with white.

Nuccio includes Satsuki azaleas in his list of recommendations. These Japanese azaleas extend the bloom season since they start blooming in late May or June, when most other azaleas varieties finish their colorful display. They also will tolerate more sun than many other varieties.

Azalea blossoms can be enjoyed indoors as well as in the garden. Blossoms, especially of the heavier petaled varieties, can be floated in water for up to a week. Flowering branches can be displayed in vases. Be sure to re-cut the stem under water.